Why are whales in danger of extinction, but not chickens?

Seldom does a year pass without street demonstration by environmental activists decrying international hunting that threatens extinctions for many large marine mammals’ species. Yet to my knowledge there has never been a demonstration exhorting us to save chickens. Why not? The short answer is that chickens have never been an endangered species. But that just raises the question of why one species is endangered and another not. Whales’ populations have been dwindling because no one owns whales. They swim in international waters, and several nations have refused to respect the international treaties that have attempted to protect them. Japanese’s and Norwegian whalers understand perfectly well that their current practices threaten the survival of whales and hence their own livelihood. But each whaler also knows that any whale he does not harvest will be taken y someone else. Thus no whaler stands to gain from self-restraint. In contrast, most chickens in the world are owned by someone. If you kill one of your chickens today, that is one less chicken you own tomorrow. If chicken farming were your livelihood, you would have strong incentives to balance the number of birds you send to the market and the number of chicks you would acquire. Chickens and whales are both economically valuable. The fact that people enjoy secure property rights in chickens but not in whales explains why the former are secure and the latter are endangered.